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1 | /* |
2 | * ADX ADPCM codecs | |
3 | * Copyright (c) 2001,2003 BERO | |
4 | * | |
5 | * This file is part of FFmpeg. | |
6 | * | |
7 | * FFmpeg is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; either | |
10 | * version 2.1 of the License, or (at your option) any later version. | |
11 | * | |
12 | * FFmpeg is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with FFmpeg; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include "avcodec.h" | |
23 | #include "adx.h" | |
24 | #include "bytestream.h" | |
25 | #include "internal.h" | |
26 | #include "put_bits.h" | |
27 | ||
28 | /** | |
29 | * @file | |
30 | * SEGA CRI adx codecs. | |
31 | * | |
32 | * Reference documents: | |
33 | * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html | |
34 | * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ | |
35 | */ | |
36 | ||
37 | static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, | |
38 | ADXChannelState *prev, int channels) | |
39 | { | |
40 | PutBitContext pb; | |
41 | int scale; | |
42 | int i, j; | |
43 | int s0, s1, s2, d; | |
44 | int max = 0; | |
45 | int min = 0; | |
2ba45a60 DM |
46 | |
47 | s1 = prev->s1; | |
48 | s2 = prev->s2; | |
49 | for (i = 0, j = 0; j < 32; i += channels, j++) { | |
50 | s0 = wav[i]; | |
51 | d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; | |
2ba45a60 DM |
52 | if (max < d) |
53 | max = d; | |
54 | if (min > d) | |
55 | min = d; | |
56 | s2 = s1; | |
57 | s1 = s0; | |
58 | } | |
2ba45a60 DM |
59 | |
60 | if (max == 0 && min == 0) { | |
f6fa7814 DM |
61 | prev->s1 = s1; |
62 | prev->s2 = s2; | |
2ba45a60 DM |
63 | memset(adx, 0, BLOCK_SIZE); |
64 | return; | |
65 | } | |
66 | ||
67 | if (max / 7 > -min / 8) | |
68 | scale = max / 7; | |
69 | else | |
70 | scale = -min / 8; | |
71 | ||
72 | if (scale == 0) | |
73 | scale = 1; | |
74 | ||
75 | AV_WB16(adx, scale); | |
76 | ||
77 | init_put_bits(&pb, adx + 2, 16); | |
f6fa7814 DM |
78 | |
79 | s1 = prev->s1; | |
80 | s2 = prev->s2; | |
81 | for (i = 0, j = 0; j < 32; i += channels, j++) { | |
82 | d = ((wav[i] << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; | |
83 | ||
84 | d = av_clip(ROUNDED_DIV(d, scale), -8, 7); | |
85 | ||
86 | put_sbits(&pb, 4, d); | |
87 | ||
88 | s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS; | |
89 | s2 = s1; | |
90 | s1 = s0; | |
91 | } | |
92 | prev->s1 = s1; | |
93 | prev->s2 = s2; | |
94 | ||
2ba45a60 DM |
95 | flush_put_bits(&pb); |
96 | } | |
97 | ||
98 | #define HEADER_SIZE 36 | |
99 | ||
100 | static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize) | |
101 | { | |
102 | ADXContext *c = avctx->priv_data; | |
103 | ||
104 | bytestream_put_be16(&buf, 0x8000); /* header signature */ | |
105 | bytestream_put_be16(&buf, HEADER_SIZE - 4); /* copyright offset */ | |
106 | bytestream_put_byte(&buf, 3); /* encoding */ | |
107 | bytestream_put_byte(&buf, BLOCK_SIZE); /* block size */ | |
108 | bytestream_put_byte(&buf, 4); /* sample size */ | |
109 | bytestream_put_byte(&buf, avctx->channels); /* channels */ | |
110 | bytestream_put_be32(&buf, avctx->sample_rate); /* sample rate */ | |
111 | bytestream_put_be32(&buf, 0); /* total sample count */ | |
112 | bytestream_put_be16(&buf, c->cutoff); /* cutoff frequency */ | |
113 | bytestream_put_byte(&buf, 3); /* version */ | |
114 | bytestream_put_byte(&buf, 0); /* flags */ | |
115 | bytestream_put_be32(&buf, 0); /* unknown */ | |
116 | bytestream_put_be32(&buf, 0); /* loop enabled */ | |
117 | bytestream_put_be16(&buf, 0); /* padding */ | |
118 | bytestream_put_buffer(&buf, "(c)CRI", 6); /* copyright signature */ | |
119 | ||
120 | return HEADER_SIZE; | |
121 | } | |
122 | ||
123 | static av_cold int adx_encode_init(AVCodecContext *avctx) | |
124 | { | |
125 | ADXContext *c = avctx->priv_data; | |
126 | ||
127 | if (avctx->channels > 2) { | |
128 | av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n"); | |
129 | return AVERROR(EINVAL); | |
130 | } | |
131 | avctx->frame_size = BLOCK_SAMPLES; | |
132 | ||
133 | /* the cutoff can be adjusted, but this seems to work pretty well */ | |
134 | c->cutoff = 500; | |
135 | ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, | |
141 | const AVFrame *frame, int *got_packet_ptr) | |
142 | { | |
143 | ADXContext *c = avctx->priv_data; | |
144 | const int16_t *samples = (const int16_t *)frame->data[0]; | |
145 | uint8_t *dst; | |
146 | int ch, out_size, ret; | |
147 | ||
148 | out_size = BLOCK_SIZE * avctx->channels + !c->header_parsed * HEADER_SIZE; | |
149 | if ((ret = ff_alloc_packet2(avctx, avpkt, out_size)) < 0) | |
150 | return ret; | |
151 | dst = avpkt->data; | |
152 | ||
153 | if (!c->header_parsed) { | |
154 | int hdrsize; | |
155 | if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) { | |
156 | av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n"); | |
157 | return AVERROR(EINVAL); | |
158 | } | |
159 | dst += hdrsize; | |
160 | c->header_parsed = 1; | |
161 | } | |
162 | ||
163 | for (ch = 0; ch < avctx->channels; ch++) { | |
164 | adx_encode(c, dst, samples + ch, &c->prev[ch], avctx->channels); | |
165 | dst += BLOCK_SIZE; | |
166 | } | |
167 | ||
168 | *got_packet_ptr = 1; | |
169 | return 0; | |
170 | } | |
171 | ||
172 | AVCodec ff_adpcm_adx_encoder = { | |
173 | .name = "adpcm_adx", | |
174 | .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"), | |
175 | .type = AVMEDIA_TYPE_AUDIO, | |
176 | .id = AV_CODEC_ID_ADPCM_ADX, | |
177 | .priv_data_size = sizeof(ADXContext), | |
178 | .init = adx_encode_init, | |
179 | .encode2 = adx_encode_frame, | |
180 | .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, | |
181 | AV_SAMPLE_FMT_NONE }, | |
182 | }; |